Actually rotateAxis(...) is the way to go. If you want to rotate the camera around some object at the origin, move the camera to the origin, do the rotation around the axis and move it back...like so...
cam.moveCamera(Camera.CAMERA_MOVEIN, distance);
cam.rotateAxis(axis, angle);
cam.moveCamera(Camera.CAMERA_MOVEOUT, distance);
But if you got it working in another way...